Burner control system

ABSTRACT

A burner control for a system having fluid burner, a pump, a nozzle, an air control louver with a fluid operator and a fluid bypass. A main valve connects the pump and the nozzle. A second valve connects the pump, the main valve, the louver operator and the fluid bypass, and additionally the louver operator connects with the fluid bypass. The control in operation controls the operator of an air louver apparatus and fluid flow through the nozzle and the bypass in a low fire condition and a high fire condition.

United States Patent [191 Gordon [4 1 Mar. 19,1974

[ BURNER CONTROL SYSTEM [75] Inventor: Merrill K. Gordon, Winfield, Kans.

[73] Assignee: Peabody Gordon-Piatt, Inc.,

Winfield, Kans.

22 Filed: Nov. 20, 1972 21 Appl. No.: 308,182

52 US. 01..., 431/90, 137/98 s 1 1m. C1.... F23n 3/00 58 Field of Search 431/90; 137/98 [56] References Cited UNITED STATES PATENTS 1,923,614 8/1933 Clarkson 431/90 1,961,790 6/1934 Roth et al.

2.979.124 4/1961 Kirk Primary Examiner-Carroll B. Dority, Jr. Assistant Examiner-Henry C. Yuen Attorney, Agent, or F [rm-John H. Widdowson [57] ABSTRACT A burner control for a system having fluid burner, a pump, a nozzle, an air control louver with a fluid operator and a fluid bypass. A main valve connects the pump and the nozzle. A second valve connects the pump, the main valve, the louver operator and the fluid bypass, and additionally the louver operator connects with the fluid bypass, The control in operation controls the operator of an air louver apparatus and fluid flow through the nozzle and the bypass in a low fire condition and a high fire condition.

9 Claims, 3 Drawing Figures BURNER CONTROL SYSTEM Numerous types of burner fluid fuel control systems are known in the prior art as operable to control the flow of combustible fluid to a burner nozzle. These prior art devices generally have a plurality of solenoid operated valves or their equivalent arranged in a fluid circuit to separately control fluid flow to the nozzle, to a pressure controller, to an air regulation device, and to a bypass or relief valve. Normally, these prior art devices operate with no less than three of such solenoid operated valves and often times have many more as well as having a complicated fluid circuit connecting the many valves and components of a burner apparatus. Some prior art burner control system use complex electro-mechanical control valves and regulators to control liquid and gaseous burner fuels and air to regulate the burner. These prior art electro-mechanical devices are not necessarily solenoid operated valves but can be an electrical solenoid-like arrangement, or may be entirely mechanical or electrical and mechanical to accomplish the controlling of a mechanical valve or the like. A device employing a number of such electromechanical valves is prone to malfunction due to the complex nature of the device. Some of the other prior art fuel control systems for burners utilize a plurality of solenoid operated valves; these also are prone to operational difficulty due to the large number of such solenoid operated valves in the system. Generally, a burner control system utilizing solenoid operated valves will have not less than three of such valves or solenoid operated devices in the system in addition to the other basic components of the system, such as the pump, nozzle, a pressure relief valve, and a device to regulate the airflow to the burner. be

In the preferred specific embodiments of the herein disclosed invention, a burnercontrol system includes two solenoid operated valves in a system which is adapted to control the supply of fuel and air to a burner. The several herein disclosed embodiments of the burner control system of this invention utilize the basic components of any fluid burner system, namely, a nozzle, a pump, a bypass or relief valve, and a fluid actuated operator for an air control louver apparatus. In a preferred specific embodiment, (l), of the burner control system of this invention, such includes a main valve connected between the pump and the nozzle, a three-way valve with the inlet connected to the pump, one outlet connected to the bypass valve, and the other outlet connected to a normally retracted fluid cylinder operator for the louver apparatus, with the fluid cylinder in turn being connected to the bypass valve. In another preferred specific embodiment, (2), of the burner control apparatus of this invention, such includes a main valve connected between the pump and the nozzle, and a three-way valve having its inlet connected to the pump and having one outlet connected to a normally extended fluid cylinder for operation of the air louver, the other outlet of the three-way valve being connected to the bypass valve with the cylinder being connected to the bypass valve. In another specific embodiment, (3), of the burner control system of this invention, such includes a main valve having the inlet thereof connected to the pump and the outlet thereof connected to the nozzle, and a second valve having the inlet thereof connected to the pump and the outlet thereof connected to a normally retracted cylinder used with the air louver, and the cylinder being in turn connected with the bypass valve. In the use and operation of the herein disclosed embodiments of the invention, each is constructed and adapted to provide burner fuel at a low nozzle pressure with the air regulating lou ver set for a low fire condition, and additionally the system is adapted to provide burner fuel at a high nozzle.

pressure with the air regulating louver set for a high fire condition. y

One object of this invention is to provide a burner control system overcoming the aforementioned disadvantages of the prior art devices.

Still, one other object of this invention is to provide a burner control system utilizing two solenoid actuated valves for control of fluid flow to the nozzle and the opening and closing of an air control louver apparatus.

One other object of this invention is to provide a burner control system having a fluid pump with a high pressure regulator therein a nozzle, a bypass valve, a fluid actuated air control operator, and two solenoid actuated valves for control of fluid to the nozzle and to the fluid operator of the airflow louver apparatus so as to provide a low fire burner condition with low fluid pressure at the nozzle and the air louver closed and to provide a high fire condition with high fluid pressure at the nozzle and the air louver open.

Yet, another object of this invention is to provide a burner control system having a normally closed solenoid actuated valve controlling fluid flow to the nozzle; and having a three-way solenoid actuated valve controlling fluid flow to the bypass valve and to the air louver operator with one position of the three-way valve to direct fluid to the bypass valve so as to provide a low fire condition with the air louver closed and the fluid pressure low, and another position of the three-way valve so as to direct fluid to the air louver operator to open same and provide a high fluid pressure and a high fire condition.

Yet, another object of this invention is to provide a burner control system having a normally closed solenoid actuated valve controlling fluid flow to the nozzle; and having a solenoid actuated three-way valve directing fluid flow to the bypass valve and to the air control operator for a low pressure, low fire condition or directing the fluid to an oil return for a high pressure, high fire condition.

Yet, another object of this invention is to provide a burner control system having a normally closed solenoid actuated valve controlling fluid flow to the nozzle, and having another normally closed solenoid actuated valve controlling fluid flow to the air control operator which is in turn connected with the bypass valve with opening and closing of the second valve the means to raise and lower the fluid pressure and control the air louver opening.

Various other objects, advantages, and features of the invention will become apparent to those skilled in the art from the following discussion, taken in conjunction with the accompanying drawing, in which:

FIG. 1 is a pictorial diagram of the first described preferred specific embodiment, (1), such shown with the air control louver in the closed position;

FIG. 2 is a pictorial diagram of the second described preferred specific embodiment, (2), of the invention, same shown with the air control louver partially open; and

The following is a discussion and description of pre-.

ferred specific embodiments of the burner control system of this invention, such being made with reference to the drawing, whereupon the same reference numerals are used to indicate the same or similar parts and/or structure. It is to be understood that such discussion and description is not to unduly limit the scope of the invention.

Referring to the drawing in detail and in particular to FIGS. 1, 2, and 3, the several embodiments of the control system of this invention are shown in a pictorial form. The first described preferred specific embodiment, (1), is shown in FIG. 1 and generally indicated at the second described preferred specific embodiment of the invention is shown in FIG. 2 and generally indicated at 12; and the third described preferred specific embodiment of the invention is shown in FIG. 3 and generally indicated at 14. In basic operation all of the herein disclosed preferred specific embodiments of the oil control system operate in a similar fashion; that is, they have a low fire condition wherein fuel at low pressure is supplied at the nozzle and the air control is closed to restrict the amount of air introduced into the burner; and they have a high fire condition, wherein fuel at high pressure is supplied at the nozzle and the air control louver is opened to supply a large amount of air to the burner. The severalembodiments of the invention include several elements which are basic elements of any burner apparatus and the fuel supply system therefor; these elements are common to each of the embodiments. The common elements of the several embodiments include a pump apparatus 16, the fuel discharge nozzle 18, the bypass or fuel pressure relief valve 20, and the air control or louver apparatus 22 including its hydraulic operator cylinder 24. In the hereinafter description the common elements of the several embodiemnts will bear the same numerals in all the figures of the several embodiments. In the hereinafter description of the several embodiments ofthis invention, such is made with reference to oil as the operating fuel; it is to be understood that such is not to restrict use of the control system to oil alone or prevent its use with other liquid or liquifiable fluid fuels.

In the first preferred specific embodiment, (1), such is shown in detail in FIG. 1. Basic elements of the burner control system should be noted atthis point since they are similar to all the herein described embodiments of the invention. The pump 16 is connected to an oil supply by line 30 and has a shut-off valve 32 to control the supply of fuel. The pump 16 has an integral pressure regulating apparatus whereby a maximum pressure for the discharge can be regulated within the pump and a pressure relief apparatus to dump fluid back to the reservoir if necessary..The pump 16 has an external pressure regulating adjuster 34, an output pressure gauge 36 at the outlet 38 and a relief return line 30 at the return outlet 42. The nozzle 18 is preferably a simplex type nozzle. The bypass valve 20 is an adjustable pressure regulating valve referred to hereinafter as a bypass valve. The bypass valve 20 is used to regulate the fuel pressure when the control system is in the low fire mode of operation. The air control apparatus consists of a duct 44 with a louver 46 mounted therein so as to be moved into a closed or open position by a spring 48 depending upon the particular embodiment of the invention. It has an actuator arm 50 connected with the louver 46 to be moved by the hydraulic operator cylinder 24. The actuator arm 50 is mounted with the louver 46 so movement of the cylinder piston rod will cause it to open or close the duct passageway, depending upon the particular embodiment of the invention. The air control louver hydraulic operator 24 has a cylinder 52 with a piston 54 and push rod 56 contained therein and has a spring 58 within the cylinder 52. The operator is either a normally extended type or normally retracted type depending upon the particular embodiment of the invention. In the first described embodiment, (1), shown in FIG. 1 the operator 24 is normally retracted and has the spring 58 positioned between the piston 54 and the end of the cylinder 52 closing the air louver 46.

In addition to the basic elements of the burner control system the first preferred specific embodiment, 1), includes a main valve 60 and a second valve 62 connected in the fluid circuit in the position shown in FIG. 1. The control circuit as shown in FIG. 1 includes a pump outlet conduit 64 from the pump outlet 38 connected by a tee 66 to the main valve 60 and the second valve 62.'A conduit 68 joins the .tee 66 to the main valve inlet and another conduit 69 connects the main valve outlet to the nozzle 18. The second valve 62 is a solenoid actuated three-way valve having two positions; this valve has its inlet 70 joined to the tee 66 by a conduit 72. One position outlet of the second valve 62 is indicated at 74 and has a conduit 76 connected to same which joins it with the pressure regulating valve 20. The other outlet of the second valve 62 is indicated at 78 andhas a conduit 80 connected thereto joining same with the air control operator 24 at the cylinder inlet 82 below the piston 54. A tee 84 at the cylinder inlet 82 provides a means to connect the conduit 80 with the cylinder 52 of the operator 24; it has another conduit 86 extending from its opposite side connected to an orifice section 88. The orifice section 88 provides means to restrict oil flow through the conduit 80 to insure that the operator 24 maintains the proper extended position when in operation. The orifice section 88 may or may not he necessary depending upon the specific oil cylinder and flow rate but is shown here to illustrate that such may be necessary. A conduit 90 connects the orifice section 88 to a tee 92 and an oil return line .94. The tee 92 in the oil return line is connected with the bypass valve 20 by a conduit 96 to provide a discharge from the bypass valve 20 through the conduit 96 into the oil return line 94. The oil return line 94 passes oil back to the storage reservoir.

In normal operation of the burner control system 10, such assumes two modes of operation, a low fire condition and a high fire condition. The low fire condition is used for startingof a furnace and maintaining the furnace at a low temperature if such is necessary. In the low fire conditon, the air control 22 is closed and the nozzle 18 is supplied with fuel at a low pressure. In practice the pressure of the oil at the nozzle 18 in this condition is set for the desired, low fire rate between 80 to pounds per square inch gauge. When operating in the low fire condition, the main valve 60 is opened to allow oil to pass to the nozzle 18, and the second valve 62 is positioned to pass oil from its inlet 70 to the outlet 74 thereby directing same through the conduit 76 to the bypass valve 20. Oil flows from the pump outlet 38 into the conduit 64, through the conduit 68, the main valve 60, the conduit 69 through the nozzle 18 and is discharged into the burner flame area for combustion. Additionally, oil flows through the tee 66, the conduit 72, the second valve 62, the conduit 76, bypass valve 20, and on into the oil return line 94. At the time the control system is in the low fire condition the conduit 80, air louver operator 24, and conduit 90, are not in the operating part of the fluid circuit and are at a residual pressure. When the control system 10 is changed to the high fire condition, the second valve 62 is actuated so the flow will be diverted from the outlet 74 to the other outlet 78; at such time the louver operator 24 is actuated by being filled with oil thus opening the air control. Additionally, the operating pressure in the oil discharge through the nozzle will increase since oil is no longer diverted through the bypass valve 20. In the high fire condition, the pressure is governed by the pressure regulating apparatus within the pump 16 and is controlled by the pressure adjusting screw 34. In practice a high fire operating pressure of between 200 and 300 pounds per square inch gauge has been found compatible with conventional burner structures. When operating in the high fire condition, the oil flows from the pump outlet 38 to the tee 66, through the conduit 68, to the main valve 60, then through the conduit 69 and is discharged through the nozzle 18 into the burner for combustion. A portion of the oil passes to the second valve 62 by moving from the tee 66 through the conduit 72 into the second valve 62 and is discharged through the outlet 78 into the conduit 80 whereupon it passes into the oil cylinder 62 below the piston 54 causing the push rod 56 to be extended thereby opening the louver 46 and the air duct 44. Oil is substantially restricted from passing on through the conduit 80 from the tee 84 to the oil return line 94 by the orifice section 88. Restriction of this oil flow insures full extension of the cylinder push rod 56 and maintains the louver 46 in open position. When in the high fire condition, the oil pressure in the conduit 76 between the second valve 62 and bypass valve and the other conduits connected with the bypass valve are at a pressure below the operating pressure.

In the event that the low fire condition is again desired when the system 10 is operating in the high fire condition, the second valve 62 is actuated to divert the flow from the outlet 78 to the outlet 74; this causes fluid to stop flowing into conduit 80, thus alleviating pressure in that conduit and the air control operator 24 as well. The conduits connected to the nozzle 18 also have the pressure reduced since flow is now regulated by the bypass valve 20, which is normally set at between 100 and 125 pounds per square inch gauge. Once the second valve 62 is actuated to divert the fluid flow to the outlet 74, the pressure drop causes the operator 24 to retract the push rod 56 thereby closing the louver 46 and the air duct 44, consequentially reducing the amount of air supplied to the burner. Since the fluid pressure is decreased, the quantity of oil supplied to the burner through the nozzle 18 is reduced. If the control system 10 is again desired in the high fire condition, the second valve 62 is actuated to divert flow from the inlet 70 to the other outlet 78 as previously described wherein the airflow through the duct 44 is again increased and operating pressure through the. nozzle 18 is increased as previously described.

The second preferred specific embodiment, (2), of the oil control system of this invention is shown in FIG. 2 and generally indicated at 12. The oil control system 12 is generally similar to the first described oil control system 10; however, it differs in the specific connected relationship of the elements. The control system 12 has the conduit from the outlet of the pump 38 joining a tee 102 which separates the flow between the main valve 104 and the second valve 106. Oil flow to the main valve 104 is through a conduit 108 connected with the tee 102; and flow from the main valve 104 to the nozzle 18 is through another conduit 1 10. The main valve 104 is a solenoid actuated valve with a normally closed position and is opened when the system 12 is started. The second valve 106 is a three-way solenoid actuated valve having two positions, one position being to operate the control system 12 in a low fire condition and the other to operate the system in the high fire condition. The second valve 106 has an inlet 107, a first position outlet 109 and a second position outlet 111. The second valve 106 has the inlet 107 connected by conduits 100 and 112 and the tee 102 so it will receive fluid from the pump 16. The seocnd valve 106 has the outlet 111 connected with a conduit 114 which joins a tee 116 connected with an oil return line 118. The first position outlet l09 of the second valve 106 is connected with a conduit 120 which is in turn connected to a tee 122 at the air control operator 24. The tee 122 is connected with a conduit 124 to provide fluid flow into the cylinder 52 of the operator at the point below the piston 54. The operator 24 has the piston rod 56 normally retracted. The tee 122 is connected with another conduit 126 joining it to the bypass valve 20, and the bypass valve 20 is connected by a conduit 128 to a tee 116 and in turn the oil return line 118.

In normal operation of the control system 12 of this invention, it has a low fire mode and a high fire mode of operation similar to the modes of operation of the first described embodiment oil control system 10 of the invention. The air louver control 22 used with the burner control system 12 of this embodiment is constructed so as to be closed when fluid is in the loop of the circuit with the louver operator 24 and open when the fluid is in the other loop. The operator 24 is normally retracted unless fluid pressure is applied; in the normally retracted condition the piston rod 56 is within the cylinder 52, and the spring 48 forces the louver 46 to an open position in the air duct 44. In the low fire condition the main valve 104 is open, and the second valve 106 is positioned to direct fluid from its inlet 107 to the outlet 109 and through the inner loop of the circuit as shown in FIG. 2. Oil passing to the nozzle 18 travels from the pump outlet 38 through the conduit 100, the tee 102, conduit 108, through the main valve 104, and the conduit into the nozzle 18 where it is atomized into the combustion section of the burner apparatus. Oil moves through the inner louver circuit from the tee 102 through the conduit 112, the second valve 106, the conduit 120, into the tee 122 through the conduit 124 and into louver operator 24, through the conduit 126, into the bypass valve 20, through the conduit 128, and tee 116 and on into the oil return line 1 18. The bypass valve 20 regulates the flow through the inner loop and dumps oil into the return line at a relatively low pressure. Oil passing into the operator 24 is below the piston 54 within the cylinder 52 and compresses the spring 58 in pushing the piston rod 56 upward thereby closing the louver 46 in the air duct 44 thus restricting airflow to the burner apparatus. In the low fire condition the operating pressure at the nozzle 18 is governed by the setting of the bypass valve 20 since it is the means by which oil is dumped in the return line 118. In practice it has been found that the bypass valve 20 should be set in the range of 80 to 140 pounds per square inch gauge since such is compatible with conventional burner apparatuses generally.

in the high fire mode of operation of the burner control system 12, fluid flow is through the outer loop of the circuit shown in FIG. 2. In the high fire condition the main valve 104 is open and the second valve 106 is positioned to pass fluid from its inlet 107 to the outlet 111. In this high fire condition oil passes to the nozzle 18 by the same means as in the low fire condition and oil passes to the second valve 106 through the conduit 112. Oil leaves the second valve 106 through the ocnduit 114 and is passed to the oil return conduit 118 through the tee 116. In the high fire mode of operation the operating pressure at the nozzle 18 is substantially higher than it is in the low fire mode of operation. In practice is has been found that a high fire nozzle pressure in the range of 200 to 300 pounds per square inch gauge is preferable. The oil pressure inthe high fire mode is determined by the pressure regulating device within the pump 16. High pressure in this mode is achieved by utilizing back pressure of the second valve 106 in combination with the pump 16. In the event that the restriction of the second valve 106 is not sufficient to permit the desired pressure, an orifice section may be installed in the conduit 114 to further restrict the flow and thus enable the pump 16 to provide the desired nozzle pressure. The optional orifice section is not shown in the drawings. Additionally, when in the high fire mode of operation, only residual pressure is present in the inner loop of the circuit; thus the air control louver apparatus 22 has the louver 46 in the open position within the air duct 44 thus allowing free flow of air to the burner apparatus. The operator 24 is in its normally retracted position.

During the normal operation of the burner control system 12, it may be necessary to switch between the high fire mode and the low fire mode or vice versa.

Normally, the low fire mode is used for starting and initially firing the furnace after the pre-purge cycle. On initial starting of the burner the control system 12 is put in the low fire mode of operation; then after a flame is proved, it is switched to the high fire mode of operation by simply actuating the solenoid operated second valve 106 to switch the fluid to flow from outlet 111 instead of outlet 109 as previously described. Switching from the low fire mode to the high fire mode increases nozzle pressure and opens the air control 22 for increased airflow at the same time. The increased fluid pressure occurs similtaneously with increasing airflow. When it is desired to switch from the high fire mode of operation back to the low fire mode of operation, the solenoid actuated second valve 106 is activated to change positions so the fluid output from it is switched from the outlet 111 to the outlet 109 thereby returning the system to the low fire condition. ln this change from the high fire mode of operation to the low fire mode of operation. the reduction in nozzle pressure and the reduction in airflow will occur simultaneously.

The third preferred specific embodiment, (3), of the oil control system of this invention is shown in FIG. 3

and generally indicated at 14. The oil control system 14 has the same modes of operation as those heretofore described, namely, high fire mode and low fire mode. The control system 14 includes a pump 16, bypass valve 20, and airflow control apparatus 22 and operator 24 similar to the other heretofore described preferred specific embodiments, (1 and 2), of the invention. This control system 14 has a normally closed solenoid actuated main valve 140 and another normally closed solenoid actuated second valve 142. The control system 14 is generally similar to the heretofore described embodiments of the oil control system; however. it differs in the specific connected relationship of the elements. Oil flow to the. nozzle 18 is through a conduit 144 leading from the pump outlet 38, a tee 146, another conduit 148 joined with the inlet of the solenoid actuated main valve 140, and a conduit 150. The second valve 142 is connected to the pump 16 from the tee 146 by a conduit 152. The outlet of the second valve 142 is connected by a conduit 154 to a tee 156 and through a conduit 158 to the air control operator 24. The air control operator cylinder 52 is connected by the conduit 158 to the tee 156. The other side of the tee 156 is connected to a conduit 160 connecting it with the bypass valve 20. An oil return line 162 is connected with the bypass valve 20 and provides an oil return to the reservoir. The main valve 140 is similar to the heretofore described main valves of the other control systems and is a normally closed valve. The second valve 142 may be either a normally closed type valve which will require energizing for the low fire mode of operation or a normally open type valve which will require energizing for the high fire mode of operation. In order to provide for a clearer description of the invention the second valve 142 is described in the hereinafter as a normally closed type valve. The second valve 142 is placed in the fluid circuit to control oil flow to the air control operator 24 and the bypass valve 20. The air control louver 22 has a normally open position, and the operator 24 has a normally retracted position which are assumed when the second valve 142 is closed. If the burner apparatus has a pre-purge cycle, both the main valve and second valve 142 remain closed and air passes freely through the normally open air control louver 22.

In the low fire mode of operation for the control system 14 the main valve 140 and second valve 142 are opened; the air control louver apparatus 22 is closed and fuel is supplied to the nozzle 18 at a relatively low pressure. Oil moves from the pump 16 through the outlet 38 in a conduit 144 to the tee 146 whereupon a portion of the fluid passes through the conduit 148, the main valve 140, the conduit 150 and is discharged through the nozzle 18; and the other portion of the oil passes through the conduit 152, second valve 142, conduit 154, the tee 156 through conduit 158 and into the louver operator 24; fluid also passes from the tee 156 through the conduit 160 and into the bypass valve 20. Pressure at the nozzle is regulated by the setting of the pressure relief valve or bypass valve 20. As fluid pressure rises in the operator cylinder 52, the push rod 56 is extended thereby closing the louver 46 in the air duct 44. Oil released from the bypass valve 20 passes into the oil return 162. In practice it has been found that a nozzle pressure of 80 to 140 pounds per square inch gauge is desirable in the low fire mode of operation;

this is adjustable by means of the adjustable bypass valve.

In the high fire mode of operation for the control system 14, the main valve 140 is open and the second valve 142 is closed and oil is supplied to the nozzle at a relatively high pressure. With the second valve 142 closed no oil will flow through the conduit 154, but oil will flow through the conduits connected with the nozzle 18. Specifically, oil flows through conduit 144 from discharge 38 of the pump 16, through the tee 146, the conduit 148, main valve 140, conduit 150 and into the nozzle 18 where it is discharged into the combustion section of the burner apparatus. Oil pressure in the high fire mode of operation is regulated by the pressure regulating apparatus of the pump 16 which is controllable by the adjuster 34. A discharge from the pump is provided through the outlet 42 and conduit 40 into the return line 162 as an overflow which is used in regulating the output pressure from the pump when in the high fire mode of operating the nozzle pressure. Since there is no operating pressure past the second valve 142, the air louver operator 24 returns to tis normal position with the push rod 56 retracted and louver 46 turned so that air will freely flow through the duct 44. When it is desired to switch from the high fire mode of operation to the low fire mode of operation, the solenoid actuated second valve 142 is activated so as to be opened; this causes oil to flow through the valve and into the air control operator 24 and through the bypass valve 20 as previously described. Simultaneously with opening ofthe second valve 142 the nozzle pressure will decrease, and the operator 24 will cause the push rod 56 to extend thereby reducing airflow through the duct 44 and return the maximum pressure control to the bypass valve 20. After a short transition period the control system 114 will again be operating in the low fire mode of operation as previously described. In the normal use of the control system 14 of this invention, it is operated similarly to the control system of the other embodiments described herein with regard to the initial starting and in-fire controlling of the burner by means of the control system.

In normal operation and use of the burner control system of this invention, its several embodiments are disclosed herein; the general operation of the system is very similar for all. The control system in practice has been used with burners which are adapted to burn only oil or burn oil or gas or the combination thereof. Normally, the burner control system of the invention functions with the electrical control system of a burner apparatus and the other components of a burner apparatus such as the blower and flame detector, etc. In the normal operation of a burner starting from an unfired condition, the burner is pre-purged in a cycle then the control system is set to the low fire condition whereupon a flame is ignited in the burner to start the operation. A flame detector proves the flame and the flame igniter is de-energized, and then the control system is actuated to place the system in the highfire condition thus raising the nozzle pressure and opening the air control louver 24 in the air duct 44 to admit more air as is necessary for combustion. When in the high fire condition, the pressure at the nozzle is determined by the pressure regulating apparatus of the pump 16 and is substantially higher than the nozzle pressure when the control system is in the low fire mode of operation. The outlet pressure from the pump can be read on the gauge 36 which is provided for monitoring the pump outlet pressure and properly adjusting it by the pressure regulating adjuster 34. When the control system is in the high fire mode and it is desired that the burner temperature be lowered, such as when the nominal operating pressure for a boiler is reached, the system is actuated causing return to the low fire condition wherein the nozzle pressure drops and the air controller closes the louver in the air duct. In the event the low fire mode of operation cannot maintain the desired conditions, the control system is again actuated to return the system to the high fire mode of operation thereby increasing the burners heat output. The specific means by which the control system of this invention is actuated includes a separate system of temperature sensing devices, relay circuits, etc., which are not a part of this invention yet do function with the solenoid actuated valves in the fluid circuit thereof.

In manufacture of the control system of this invention, it is obvious the system functions in the same manner as prior art fluid control systems for burners and can be produced at a lower cost and with fewer components to achieve the end product. The control system utilizes only two solenoid actuated valves in the fluid circuit along with other standard and necessary components of any such circuit, namely, the nozzle, the pump, the bypass or pressure regulating valve, and the air controller. The manufacture of the control system of this invention has the obvious advantage that it can be pro-' duced with substantially less plumbing and electrical controls than other prior art systems since it utilizes only two solenoid actuated valves.

In the use and operation of the control system of this invention, it is seen that same provides a simple and efficient means to control a fluid burner. Operation of the control system is relatively simple since it involves the deliberate actuation of only two solenoid actuated valves to control operation of the system between a low fire mode of operation and a high fire mode of operation. The use and operation of the three herein disclosed preferred specific embodiments of the control system of this invention are similar in use and operation from the basic standpoint, although they differ slightly in the circuit configuration. Use of the three herein disclosed embodiments of the invention can be to pump oil or other combustible liquids or gaseous fluids used in burner operations, although operation of the system is described as using oil as the operating fluid therefor. Overall operation of the system is somewhat safer than conventional systems utilizing three or more solenoid actuated valves in that this control system has fewer components to fail thereby lowering the possibility of failure as a safety factor.

As will become apparent from the foregoing description of the applicants oil control system, relatively simple and comparatively inexpensive means have been provided to control the fuel supply to a burner. The control system is economical in that it uses only two solenoid actuated valves in the fluid circuit, thus cuts expense in the initial investment by having fewer components in the fluid control circuit, thus necessitating fewer components and electrical circuits to control the fluid circuit of a burner. The control system is simple to use for the similar reasons, namely, that it has only two solenoid actuated valves to be controlled during its operation and only one valve need be controlled or changed in order to change the mode of operation of the control circuit. The control system provides a means to fire a burner at a low fire condition and a high fire condition and alternate between the two wherein the fluid pressure at-the nozzle is controlled as well as the airflow to the burner by the simple actuation of one solenoid actuated valve.

While the invention has been described in conjunction with preferred specific embodiments thereof, it will be understood that this description is intended to illustrate and not limit the scope of the invention, which is defined by the following claims.

I claim:

1. In a fluid burner apparatus having a pump means, a nozzle, an air control louver means with a fluid operator, and a fluid bypass means, the improvement of a burner fluid control system therefor, comprising:

a. a main valve means connected in fluid communication with said pump means and said nozzle,

b. a second valve means connected in fluid communication with said pump means, said main valve means, said louver means operator and said fluid bypass means, and

0. means connecting said louver means operator and said fluid bypass means,

said control system is adapted in operation to control said louver means operator and fluid flow through said nozzle.

2. The control system of claim 1, wherein:

a. said pump means has means to regulate the maximum operating pressure thereof,

b. said bypass means has means to return the fluid to a fluid reservoir at a predetermined pressure, and

c. said air control louver means operator has means to open and close an air louver apparatus of said burner apparatus.

3. The control system of claim 2, wherein:

a. said main valve means is constructed and adapted in operation to start and stop fluid flow to said nozzle, and

b. said second valve means is constructed and adapted in operation to control fluid flow to said louver means operator.

4. The control system of claim 3, wherein:

a. said louver means operator has a normally retracted fluid cylinder means operable on receipt of fluid under pressure to extend, and

b. said bypass means is a pressure relief valve means constructed and adapted in operation to open at a specified pressure thereby passing fluid to said reservoir.

5. The control system of claim 4, wherein:

a. said pump means has an inlet in fluid communication with said fluid reservoir, a main outlet having said means to regulate pressure, and a return outlet connected by a conduit means to said bypass means,

b. said main valve means is a normally closed valve having an outlet connected by a conduit means to said nozzle, and having an inlet connected by a conduit means to said pump means main outlet,

c. said second valve means is a three-way valve having the inlet connected said pump means main outlet, one outlet connected said bypass means. the

' other outlet connected said louver means operator.

and

d. said louver means operator is connected to said oil reservoir for the return of fluid thereto when in operation.

6. The control system of claim 4, wherein:

a. said pump means has an inlet in fluid communication with a fluid reservoir, a main outlet having said means to regulate pressure, and a return outlet in fluid communication with said bypass means by a conduit,

b. said main valve means is a normally closed valve and is connected to said nozzle by means of a conduit, having an inlet conduit connecting same to said pump means main outlet by a pump conduit means,

c. said second valve means is a three-way valve having the inlet thereof connected said pump means outlet conduit, one outlet thereof connected said fluid reservoir, and the other outlet thereof connected said louver means operator, and

d. said louver means operator isconnected said bypass means.

7. The control system of claim 4, wherein:

a. said pump means has an inlet in fluid communication with a fluid reservoir, a main outlet having said means to regulate pressure and a return outlet connected by a conduit means to said bypass means,

b. said nozzle is connected via a conduit means to the outlet of said main valve means,

c. said pump means outlet is connected via a conduit to the inlet of said main valve means and the inlet of said second valve means, and

d. said louver means operator is connected via a conduit to the outlet of said second valve means and to said bypass means.

8. The control system of claim 7, wherein:

a. said main valve means is a normally closed valve,

and

b. said second valve means is a normally closed valve.

9. The control system of claim 1, wherein:

a. said main valve means is a closable and openable solenoid actuated valve, and

b. said second valve means is a closable and openable solenoid actuated valve. 

1. In a fluid burner apparatus having a pump means, a nozzle, an air control louver means with a fluid operator, and a fluid bypass means, the improvement of a burner fluid control system therefor, comprising: a. a main valve means connected in fluid communication with said pump means and said nozzle, b. a second valve means connected in fluid communication with said pump means, said main valve means, said louver means operator and said fluid bypass means, and c. means connecting said louver means operator and said fluid bypass means, said control system is adapted in operation to control said louver means operator and fluid flow through said nozzle.
 2. The control system of claim 1, wherein: a. said pump means has means to regulate the maximum operating pressure thereof, b. said bypass means has means to return the fluid to a fluid reservoir at a predetermined pressure, and c. said air control louver means operator has means to open and close an air louver apparatus of said burner apparatus.
 3. The control system of claim 2, wherein: a. said main valve means is constructed and adapted in operation to start and stop fluid flow to said nozzle, and b. said second valve means is constructed and adapted in operation to control fluid flow to said louver means operator.
 4. The control system of claim 3, wherein: a. said louver means operator has a normally retracted fluid cylinder means operable on receipt of fluid under pressure to extend, and b. said bypass means is a pressure relief valve means constructed and adapted in operation to open at a specified pressure thereby passing fluid to said reservoir.
 5. The control system of claim 4, wherein: a. said pump means has an inlet in fluid communication with said fluid reservoir, a main outlet having said means to regulate pressure, and a return outlet connected by a conduit means to said bypass means, b. said main valve means is a normally closed valve having an outlet connected by a conduit means to said nozzle, and having an inlet connected by a conduit means to said pump means main outlet, c. said second valve means is a three-way valve having the inlet connected said pump means main outlet, one outlet connected said bypass means, the other outlet connected said louver means operator, and d. said louver means operator is connected to said oil reservoir for the return of fluid thereto when in operation.
 6. The control system of claim 4, wherein: a. said pump means has an inlet in fluid communication with a fluid reservoir, a main outlet having said means to regulate pressure, and a return outlet in fluid communication with said bypass means by a conduit, b. said main valve Means is a normally closed valve and is connected to said nozzle by means of a conduit, having an inlet conduit connecting same to said pump means main outlet by a pump conduit means, c. said second valve means is a three-way valve having the inlet thereof connected said pump means outlet conduit, one outlet thereof connected said fluid reservoir, and the other outlet thereof connected said louver means operator, and d. said louver means operator is connected said bypass means.
 7. The control system of claim 4, wherein: a. said pump means has an inlet in fluid communication with a fluid reservoir, a main outlet having said means to regulate pressure and a return outlet connected by a conduit means to said bypass means, b. said nozzle is connected via a conduit means to the outlet of said main valve means, c. said pump means outlet is connected via a conduit to the inlet of said main valve means and the inlet of said second valve means, and d. said louver means operator is connected via a conduit to the outlet of said second valve means and to said bypass means.
 8. The control system of claim 7, wherein: a. said main valve means is a normally closed valve, and b. said second valve means is a normally closed valve.
 9. The control system of claim 1, wherein: a. said main valve means is a closable and openable solenoid actuated valve, and b. said second valve means is a closable and openable solenoid actuated valve. 